Differential Gearing

[nobrakese36]

well after having my rear window re-glued to its frame 150$ (could of been upgrade money), i decided to talk to the guy about better performance on my 93 318is,he said to raise the rear differential gearing for the best performance upgrade,he is currently running a 4.45 in his evo e30 m3 , so does anyone know a good place to get a differential for a 318 because its different then the 6 cyl cars, thanks

[Furious]

i believe that 318 diff is 4.44 or a 3.91 , you do get excellent performance out of it but going too high is risky, some people have to consider highway driving, for instance im looking for a 3.38 but the problem is that if i go higher then that ill be looking at very high RPMS at highway speeds.

[theruss1an1]

Id go with some FI.

-Serge

[thekid]

The auto diff is 4.44 the manual I believe is 3.71 or 3.5X, because the people that do look into upgrading their diffs, look at putting in a 3.91 (for the 5spd'ers among us). If you put the 4.44 into a 5spd 318i, your top speed will be about 88mph, but you will get there very very quickly... But yes, it would be quite cheap to do.

[buuhh99]

Yeah furious is right my cousin has a diffrent diff in his integra, tops out at 100 used to top out at 130, sucks for highway driving because he is cruzing at like 5000 rpm

[nobrakese36]

i did the math at 6400 rpm with a 3.91 final drive ratio you will be doing 120, at 5000 rpm youll be doing 80,hmmmmmmm!